Canon A700 Exposure & Imaging

Color

In the diagram above, the squares show the original color, and the circles show the color that the camera captured. More saturated colors are located towards the periphery of the graph. Hue changes as you travel around the center. Thus, hue-accurate, highly saturated colors appear as lines radiating from the center.

Most consumer digital cameras produce color that's more highly saturated (more intense) than found in the original subjects. This is simply because most people like their color a bit brighter than life. The PowerShot follows this trend, though it tends to overdo the strong red tones a bit. Where oversaturation is most problematic is on Caucasian skin tones, as it's very easy for these "memory colors" to be seen as too bright, too pink, too yellow, etc. The A700 did render skin tones a bit on the pink side in most cases, but our sense is that most consumers would find the A700's bright color very appealing.

The other important part of color rendition is hue accuracy. Hue is "what color" the color is. Here, the PowerShot did quite well. Like most digital cameras, it shifts cyan colors toward blue, to produce better-looking sky colors, but the rest of the hues were quite accurate.

Color balance indoors under Auto white balance was warm and under Incandescent lighting a bit cool. The PowerShot required a +1.0 EV exposure compensation boost to get a good exposure with Auto white balance and +0.7 EV with Incandescent. Overall color well-balanced and hue accurate. Our test lighting for this shot is a mixture of 60 and 100 watt household incandescent bulb, a pretty yellow light source, but a very common one in typical home settings here in the U.S.

Outdoor shots generally showed accurate exposure with slightly blown out highlights. Shadow detail also tended to fall apart, but nothing that would raise an alarm for a consumer digicam. Sunlit shots showed high contrast and moderate oversaturation while overcast scenes managed a more accurate portrayal. Exposure accuracy overall was better than average, the camera typically requiring less exposure compensation than we're accustomed to seeing with consumer digicams.

Our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,300 lines per picture height, with extinction at around 1,600. You could perhaps argue for 1,400 lines of resolution, but we felt that the level of artifacts there was too high to justify a rating at that level. (The camera did produce some artifacts even at lower line frequencies though, visible both below and in the full-sized res target shots.) Use these numbers to compare with other cameras of similar resolution, or use them to see just what higher resolution can mean in terms of potential detail. Beware that while you might be able to make out what looks like distinct lines at numbers higher than those we've mentioned here, the camera is just doing its best to continue interpreting the lines. If you zoom in and follow them from the wider portions, you'll see the lines converge and reappear several times, so the lines you see at 1,600 and higher are really only artifacts generated by the camera's imaging system.

The PowerShot's images are reasonably sharp, with only slight over-sharpening or edge enhancement on the camera's part. (Edge enhancement creates the illusion of sharpness by enhancing colors and tones right at the edge of a rapid transition in color or tone.)

Noise-suppression systems in digital cameras tend to flatten-out detail in areas of subtle contrast. The effects can often be seen in shots of human hair, where the individual strands are lost and an almost "watercolor" look appears. On the A700, noise suppression at shutter speeds above 1.3 seconds is fairly modest in its impact, with relatively little loss of subtle detail.

ISO & Noise PerformanceModerate noise at the normal sensitivity settings, very high noise that blurs detail at the higher settings.

ISO 80

ISO 100

ISO 200

ISO 400

ISO 800

The PowerShot A700's sensitivity ranges from ISO 80 to 800 equivalents. Up to ISO 200, the PowerShot produced very little noise, with only slightly blurred detail in the dark areas. At ISO 400 and especially at 800, the noise level and the amount of blurring that results increased noticeably. Overall though, the Canon A700's noise levels are lower than average for its class.

Extremes: Sunlit and low light testsHigh resolution with good overall detail, but high contrast and limited shadow detail under harsh lighting. Excellent low-light performance, capable of capturing bright images under average city street lighting and much darker conditions.

Normal

+0.3EV

+0.7EV

Sunlight:Because digital cameras are more like slide film than negative film (in that they tend to have a more limited tonal range), we test them in the harshest situations to see how they handle scenes with bright highlights and dark shadows, as well as what kind of sensitivity they have in low light. The shot above is designed to mimic the very harsh, contrasty effect of direct noonday sunlight, a very tough challenge for most digital cameras. (You can read details of this test here.)

The Canon A700 had a little trouble with the deliberately harsh lighting in the test above, producing somewhat high contrast with lost highlight detail and deep shadows. The A700 required a bit less exposure compensation than some competing models, as this shot usually calls for about +1.0 EV of adjustment. (In "real life" though, be sure to use fill flash in situations like the one shown above; it's better to shoot in the shade when possible.)

1 fc
11 lux

1/2 fc
5.5 lux

1/4 fc
2.7 lux

1/8 fc
1.3 lux

1/16 fc
0.67 lux

ISO
80

1.3 sec
f2.8

3.2 sec
f2.8

8 sec
f2.8

15 sec
f2.8

15 sec
f2.8

ISO
100

1 sec
f2.8

2 sec
f2.8

5 sec
f2.8

15 sec
f2.8

15 sec
f2.8

ISO
200

1/2 sec
f2.8

1 sec
f2.8

2.5 sec
f2.8

8 sec
f2.8

15 sec
f2.8

ISO
400

1/4 sec
f2.8

1/2 sec
f2.8

1.3 sec
f2.8

3.2 sec
f2.8

8 sec
f2.8

ISO
800

1/8 sec
f2.8

1/4 sec
f2.8

1/1 sec
f2.8

1.6 sec
f2.8

4 sec
f2.8

Low light:The Canon PowerShot A700 did very well in our low light tests, producing bright images at the lowest light levels at ISO 200 and above. At ISO 80 and 100, images were bright down to the 1/8 foot-candle level, about 1/8 as bright as average city street lighting at night. The one limitation though, is that you have to resort to Shutter Priority or Manual exposure mode to get exposure times longer than 1 second. As seen by the type in even the darkest images, the auto focus system worked well, relying on its AF assist lamp to find focus at the very darkest levels, but was also able to focus down at a bit less than 1/4 foot-candle without resorting to the AF assist. Given that typical city street-lighting at night is about one foot-candle (the brightest level shown in the test above), the Canon A700 should have no trouble handling the after-dark photography needs of most consumers.

NOTE: This low light test is conducted with a stationary subject, and the camera mounted on a sturdy tripod. Most digital cameras will fail miserably when faced with a moving subject in dim lighting. (For example, a child's ballet recital or a holiday pageant in a gymnasium.) For such applications, you may have better luck with a digital SLR camera, but even there, you'll likely need to set the focus manually. For information and reviews on digital SLRs, refer to our SLR review index page.

Flash

Coverage and RangeThe A700's small flash is limited to about 10 feet, and produces a slight blue cast in combination with typical incandescent room lighting. Our standard shots required roughly average exposure compensation.

35mm equivalent

210mm equivalent

Normal Flash +1.0EV

Night Portrait Mode

Flash coverage was a bit uneven at wide angle but very good at telephoto. In the Indoor test, the flash on the A700 underexposed our subject at its default setting, requiring a +1.0 EV exposure compensation adjustment to get reasonably bright results. (This is about average among cameras we test.) The camera's Night mode produced brighter results, though with a stronger pinkish-orange cast from the room lighting. Night Portrait mode required the same +1.0 EV exposure adjustment.

8 ft

9 ft

10 ft

11 ft

12 ft

13 ft

14 ft

1/60 sec
f3.5

1/60 sec
f3.5

1/60 sec
f4.0

1/60 sec
f4.0

1/60 sec
f4.0

1/60 sec
f4.5

1/60 sec
f4.5

At 11 feet, the flash did not quite illuminate the DaveBox target fully. This agrees well with Canon's own specs for the A700's flash, which state a range of 11 feet at wide angle, and 8.2 feet at telephoto, with the ISO set to Auto. (If anything, Canon's specs seem to be slightly conservative.)

Output Quality

Testing hundreds of digital cameras, we've found that you can only tell just so much about a camera's image quality by viewing its images on-screen. Ultimately, there's no substitute for printing a lot of images and examining them closely. For this reason, we now routinely print sample images from the cameras we test on our Canon i9900 studio printer, and on the Canon iP5000 here in the office. (See the Canon i9900 review for details on that model.)

With the Canon A700, we found that it had enough resolution to make very crisp 8x10 inch prints. At 13x19, its prints were a bit softer looking, but perfectly adequate for wall or table display. At high ISO, image noise levels were held in check very well up to ISO 400, but the ISO 800 shots were quite a bit noisier. We think most consumers would be quite satisfied by the quality of 8x10 inch prints made from ISO 400 shots. At ISO 800, the images looked a little rough at 5x7 (but again, probably acceptable to most consumers), and fine at 4x6 inches.

Color-wise, the PowerShot A700's images looked really great when printed on the i9900, with bright, vibrant color, yet not to the point that most users would consider it overdone. A few users who prefer more subdued, technically accurate color saturation levels may find the A700's images a little too bright, but most consumers will probably find the A700's bright, snappy images very appealing.

Not sure which camera to buy? Let your eyes be the ultimate judge!
Visit our Comparometer(tm)
to compare images from the Canon PowerShot A700 with those from other
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